We propose to develop artificial membranes containing nanoscale pores whose mechanical, electrical, and chemical properties are controlled at a nanoscale with organic molecules. The pores will be fabricated in 30-50 nm silicon nitride membranes, and as an integral component of Pt/glass nanopore electrodes. The goal of the proposed work is to covalently modify the inner walls of 5-50 nm wide nanopores with organic molecules whose size and shape are sensitive to external stimuli, such as pH, solvent polarity, pX (where X is an ion or a small molecule), external electric field, light, etc., thus producing responsive nanopores. Specific aims of the project are: (1) to develop the preparation of the nanopores in silicon nitride and in glass to the specified size; (2) to design the molecules for the responsive nanopores, and to optimize the chemistry needed for their attachment to the nanopore walls; (3) to study the stimulus-response behavior of the attached molecules and their interactions within the confines of the nanopores; and (4) to study the transport dynamics within the resulting responsive nanopores. The pores have long-range applications in stochastic biosensor devices, in separations investigations of biomolecules, and in controlled drug release devices. The proposed work is a highly innovative, design-driven effort that will lead to the creation and use of nanoscale devices with a host of biological and medical applications. This effort brings together such disciplines as organic synthesis, surface chemistry, analytical chemistry, material science, and electrical engineering.